"Flexible packaging" is used to package a large number of consumer products. Existing methods for creating flexible packaging involve printing indicia, such as logos, product information, labels, etc., on a non-rigid material, such as polypropylene, polyethylene, foil or paper. Typically, a continuous web of a selected non-rigid material in roll form is fed into a "flexographic press" which repeatedly prints the desired indicia on the passing web of non-rigid material. After printing, the web of non-rigid material is gathered in printed roll form. The printed roll is then transported to a bag converting or packaging material machine and converted to individual packaging, and the flexographic press is outfitted with a new roll of non-rigid material. This step significantly slows the process of making flexible packaging. Further, because the bag converting or packaging machines are remote from the flexographic press, the entire operation requires an unnecessarily large area.
Attempts at creating in-line printers have been prohibitive, either because the printers are too large or because the printers are incapable of repetitiously printing an image at a desired increment (knwon in the art as a "repeat"). Typically, such printers include numerous print cylinders and require a significant amount of time to set up. The present invention, by using a belt-type printer eliminates the need to store a large number of cylinders. It also offers large repeats while maintaining compactness, and the ability to print in desired increments.
Needs, therefore, exist for a printing apparatus that brings a printer "in-line" with bag converting or packaging material machines thereby eliminating the existing "out-of-line" process.
Belt-type printing machines, such as the one disclosed in U.S. Pat. No. 4,817,525 to Yagi, are well known. The Yagi belt-type printing machine includes an endless printing belt detachably wound around a plate cylinder and an adjustable tensioning roll. The plate cylinder is operated by the motor of a main drive having a power transmission system. The Yagi belt-type printing machine also includes means for synchronously controlling a printing speed of the belt-type printing machine.
While there are numerous methods and means for creating flexible packaging, none are known to be similar to, or to function in the manner of, the present invention.